Pig receiver assembly

Abstract

A pig receiver and method to retrieve pigs in pipeline pigging operations. In one embodiment, a pig receiver includes a pressure equalization system including a gate valve, wherein a first side of the gate valve is coupled to a downstream pressure connection, and wherein a second side of the gate valve is coupled to an upstream pressure connection. The pressure equalization system also includes a pressure equalization valve disposed between the downstream pressure connection and the upstream pressure connection. The pressure equalization system also includes a pig receiver unit, wherein a first side of the pig receiver unit is coupled to the downstream pressure connection downstream of the gate valve, and wherein a second side of the pig receiver unit is coupled to the upstream pressure connection upstream of the gate valve.

What is claimed: 
     
       1. A pig receiver comprising:
 a pressure equalization system comprising: 
 a gate valve, wherein a first side of the gate valve is coupled to a downstream pressure connection, 
 wherein a second side of the gate valve is coupled to an upstream pressure connection; and 
 a pressure equalization valve disposed between the downstream pressure connection and the upstream pressure connection; and 
 a pig receiver unit, wherein a first side of the pig receiver unit is coupled to the downstream pressure connection downstream of the gate valve, wherein a second side of the pig receiver unit is coupled to the upstream pressure connection upstream of the gate valve. 
 
     
     
       2. The pig receiver of  claim 1 , wherein the downstream pressure connection is disposed between the gate valve and a retrieval door. 
     
     
       3. The pig receiver of  claim 1 , wherein the pressure equalization system is configured to adjust a pressure in the pig receiver unit downstream of the gate valve. 
     
     
       4. The pig receiver of  claim 1 , wherein the pressure equalization valve is disposed about equidistant between the downstream pressure connection and the upstream pressure connection. 
     
     
       5. The pig receiver of  claim 1 , wherein the downstream pressure connection and the upstream pressure connection comprise a muffler. 
     
     
       6. The pig receiver of  claim 1 , further comprising a contaminant removal system comprising a sump disposed between the gate valve and the upstream pressure connection. 
     
     
       7. The pig receiver of  claim 6 , wherein the sump comprises sump gaps. 
     
     
       8. The pig receiver of  claim 7 , wherein the sump gaps are configured to allow contaminants to fall from the pig receiver unit to a bottom portion of the sump. 
     
     
       9. The pig receiver of  claim 8 , wherein the sump gaps are configured to not interfere with a velocity at which a pig travels in the pig receiving unit. 
     
     
       10. The pig receiver of  claim 6 , wherein the sump is configured to receive a contaminant removal fluid.